I have a Mk1 listed as # L2. It was in the USA so far and has a "small" tank , apparently 18 l or 4 imperial gallons (??) .Since races in Europe are longer, I need to either install a bigger tank or an additional tank. I guess a total of 30 l should be enough for 1 hour ( ?).However some races are 2 hours long which means 50 to 60 l to carry in case no refuelling is possible.Anyone having experience on that topic and able to advise on practical solutions?Thank you.Yves